"This is a breakthrough arrived at through hard-fought diplomacy," the State Department official said. "Just two weeks ago, no one thought this was in the vicinity of possible. After close consultation with the P3, the Russians have agreed to support a strong, binding and enforceable resolution that unites the pressure and focus of the international community on the Syrian regime to ensure the elimination of Syria's chemical weapons."

The statement goes on:

"This is historic and unprecedented because it puts oversight of the Assad regime's compliance under international control and it's the first [U.N. Security Council Resolution] to declare that the use of chemical weapons is a threat to peace and security. Equally as important, it makes absolutely clear that failure of the Assad regime to comply will have consequences. Later this evening there will be a full consultation with the UNSC to discuss text."

The full 15-member Security Council is set to meet at 8 p.m. ET. for "informal consultations."

The big issue here was what kind of language Russia would agree to, when it came to detailing the kind of consequences Syria could face if it doesn't comply with the resolution. The U.S. was looking for so-called "Chapter VII" language, which would leave the door open to military action. Russia was opposed to that.

"The resolution which will be submitted to the UN Security Council is in line with the Geneva framework on the destruction of chemical weapons in Syria," Lavrov said. "There will be no enforcement in line with Chapter 7."

Update at 7:06 p.m. ET. Debate Was Never About Use Of Force:

In an interview with CNN, State Department Spokesperson Jen Psaki said this debate "was not about the use of force."

The United States got what it was looking for, she said, which was a "strong, binding and enforceable" resolution.

"This is an important step forward," Psaki said. And there will be "consequences" if Syria fails to meet the obligations of the resolution.

Psaki was asked what those would be and Psaki said the international community has a "range of options."